Aims: β-Amyloid (Aβ)-mediated neurotoxicity plays a critical role in the pathogenesis of Alzheimer's disease (AD), possibly including Aβ-induced mitochondrial dysfunction and oxidative stress. Previous studies have demonstrated that orientin (Ori) possesses antioxidation capabilities in vitro. Therefore, current study is to demonstrate that Ori can activate Nrf2/HO-1 signaling and alleviate apoptosis induced by Aβ1-42, and ameliorate cognitive deficits in AD mice.
Main methods: AD models were made by injecting Aβ1-42 into the bilateral hippocampus of mice. The mice were randomly assigned to three groups: the normal mice and Aβ1-42-induced AD mice with saline, and Aβ1-42-induced AD mice with Ori (5mg/kg), and were injected intraperitoneally once a day for 15 days. After the Morris Water Maze (MWM) test, mice were sacrificed and brains were harvested for biochemical analysis.
Key findings: Results indicated that Ori could ameliorate cognitive deficits in AD mice. Levels of oxidative stress, indicated by production of reactive oxygen species (ROS), 3-nitrotyrosine (3-NT), 4-hydroxy-nonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), were significantly decreased after Ori treatment. In addition, the current study showed that Ori could attenuate mitochondrial dysfunction induced by Aβ1-42, and subsequently inhibited the mitochondrial apoptotic pathway. Ori induced the nuclear translocation of Nrf2, which enhanced the expression of HO-1 and activation of the redox signaling pathway.
Significance: Ori might alleviate cognitive deficits and oxidative stress in AD mice, which might be a potential therapeutic drug for AD.
Keywords: Alzheimer's disease; Nrf2/HO-1 pathway; Orientin; Oxidative stress; β-Amyloid.
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